|Publication number||US7216241 B2|
|Application number||US 10/903,429|
|Publication date||May 8, 2007|
|Filing date||Jul 30, 2004|
|Priority date||Jul 30, 2004|
|Also published as||US20060026420|
|Publication number||10903429, 903429, US 7216241 B2, US 7216241B2, US-B2-7216241, US7216241 B2, US7216241B2|
|Inventors||Samuel Martin Babb, Jeffrey Scott Weaver, Stacie F. Mathis, Kelly J. Pracht|
|Original Assignee||Hewlett-Packard Development Company, L.P.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (10), Non-Patent Citations (2), Referenced by (6), Classifications (9), Legal Events (3)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to power supplies for computers.
One common method for troubleshooting computers in the field is simply to remove suspected faulty components and to replace them with known good ones. Removed components are often then returned to the manufacturer for testing and repair. As it happens, the majority of power supply units returned in this manner are found by the manufacturers to be operating correctly upon receipt. In such cases, the power supply unit should not have been removed and replaced. It would be desirable, therefore, to provide a means by which a computer power supply can be tested for proper operation conveniently in the field.
In one aspect, a power supply unit according to a preferred embodiment of the invention is self testing. The power supply unit is enabled to function with no external loads applied, and includes a visual indicator of whether or not one or more voltage outputs of the power supply unit is within tolerance. To benefit from the self-test feature, a user in the field may simply unplug the power supply unit from all loads, plug the unit into an A/C source, and observe the visual indicator. If the visual indicator is lit, then the user may reasonably assume that the power supply unit is functioning correctly. But if the visual indicator is not lit, then the user may reasonably assume that the power supply unit is faulty.
In another aspect, a power supply unit according to a preferred embodiment of the invention may be deployed in an ATX-compliant computer. To do so, an asserted-low PS_ON# signal may be equipped with a pull-down resistor instead of a pull-up resistor inside the power supply unit. When this is done, the power supply unit will continue to function in an ATX-compliant manner in the sense that the PS_ON# signal may still be used to turn the power supply unit on and off. But when the power supply unit is disconnected from all loads and the PS_ON# signal is open-circuited at the main motherboard connector, the pull-down resistor internal to the power supply unit asserts the PS_ON# signal so that the self-test feature is enabled.
In another aspect, the visual indicator may be provided by coupling a light device to a PWR_OK signal of the power supply unit.
If computer system 100 is one that complies with the ATX standard, then voltage outputs 202 from supply 201 (referring now to
If power supply unit 302 is to be deployed in an ATX-style computer system such as computer 100, then an asserted-low control input 300 should be provided and should be operable to turn voltage outputs 302 on and off. Pull-up resistor 206, however, should not be present in power supply unit 302. Instead, pull-down resistor 306 should be provided to pull signal 300 to ground when the main power connector is unplugged from the motherboard and signal 300 is open-circuited at the connector. In this manner, power supply unit 302 will turn voltage outputs 302 on when A/C power is supplied and the main power connector is unplugged from the motherboard. But when the main power connector is plugged into the motherboard, the motherboard may overcome the pull-down provided by resistor 306 so that it may bring signal 300 high and low to turn voltage outputs 302 off and on as needed.
In order to ensure the latter functionality, it may preferable to choose a value for resistor 306 so that the internal power supply pull-down is “weak.” Some motherboards utilize a pull-up resistor on the PS_ON# signal to unassert the signal, together with an open-collector driver to assert the signal. Other motherboards use a totem pole circuit to assert and unassert the signal, but even motherboards using a totem pole circuit may also utilize a pull-up. Therefore, as an example, a value on the order of 100 k-ohm for resistor 306 may be preferable to handle cases in which a motherboard pull-up on the order of 1 k-ohm is employed. Other values may be chosen for resistor 306 as necessary given the characteristics of the circuitry on a given motherboard.
In an ATX-compliant system, level-checking circuitry 308 should be coupled at least to the +3.3 VDC, +5 VDC, and the +12 VDC voltage outputs so that PWR_OK signal 310 will indicate whether or not all of those voltage outputs are within tolerance. Optionally, level-checking circuitry may be coupled to the −12 VDC and/or the +5 VDC standby voltage outputs so that PWR_OK signal 310 may indicate the status of those outputs as well as the others.
To utilize the self-test feature provided by power supply unit 302, a user of the host computer may operate according to method 400 illustrated in
While the invention has been described in detail in relation to preferred embodiments thereof, the described embodiment has been presented by way of example and not by way of limitation. It will be understood by those skilled in the art that various changes may be made in the form and details of the described embodiment without deviating from the spirit and scope of the invention as defined by the appended claims.
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|2||ATX12V Power Supply Design Guide. Version 1.3. pp. 1-38.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7710123 *||Mar 10, 2008||May 4, 2010||Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd.||Voltage variance tester|
|US7768274 *||Nov 29, 2007||Aug 3, 2010||Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd.||Voltage tolerance measuring apparatus for motherboard|
|US7924045 *||Jul 11, 2008||Apr 12, 2011||International Business Machines Corporation||Apparatus, system, and method for error detection in a stand alone power supply|
|US20040189341 *||Mar 25, 2003||Sep 30, 2004||Liu Kevin||Power-on self test for a computer system|
|US20120079307 *||Sep 27, 2010||Mar 29, 2012||Lieberman Donald A||PSU Self-Test|
|US20140184265 *||Dec 29, 2013||Jul 3, 2014||Hon Hai Precision Industry Co., Ltd.||Test circuit for power supply unit|
|U.S. Classification||713/300, 714/22, 702/60|
|International Classification||G06F11/00, G01R21/00, G06F1/00|
|Cooperative Classification||G06F1/28, G01R31/40|
|Oct 14, 2004||AS||Assignment|
Owner name: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P., TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BABB, SAMUEL MARTIN;WEAVER, JEFFREY SCOTT;MATHIS, STACIEF.;AND OTHERS;REEL/FRAME:015247/0109;SIGNING DATES FROM 20040729 TO 20040730
|Nov 8, 2010||FPAY||Fee payment|
Year of fee payment: 4
|Oct 23, 2014||FPAY||Fee payment|
Year of fee payment: 8